OK, let's do this. We've got 517717591 and 488098543, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 3 and the borrow 0 from 1 in column 1 and get -2.
We add -2 to 10 and get 8 as the first digit of the result.

Step 2: We'll start by subtracting the digit 4 and the borrow 1 from 9 in column 2 and get 4.
4 is the next digit of our result.

Step 3: We'll start by subtracting the digit 5 and the borrow 0 from 5 in column 3 and get 0.
0 is the next digit of our result.

Step 4: We'll start by subtracting the digit 8 and the borrow 0 from 7 in column 4 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 5: We'll start by subtracting the digit 9 and the borrow 1 from 1 in column 5 and get -9.
We add -9 to 10 and get 1 as the next digit of the result.

Step 6: We'll start by subtracting the digit 0 and the borrow 1 from 7 in column 6 and get 6.
6 is the next digit of our result.

Step 7: We'll start by subtracting the digit 8 and the borrow 0 from 7 in column 7 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 8: We'll start by subtracting the digit 8 and the borrow 1 from 1 in column 8 and get -8.
We add -8 to 10 and get 2 as the next digit of the result.

Step 9: We'll start by subtracting the digit 4 and the borrow 1 from 5 in column 9 and get 0.
0 is the next digit of our result.

So, 517717591 - 488098543 = 29619048.